We propose to study the mechanisms of pituitary hormone release and production in vitro. The role of calcium in the mechanism of hormone release will be studied by estimating the effect of releasing agents on calcium flux and eventually intracellular calcium distribution, by correlating changes in calcium metabolism with hormone release and by studying the role of Na ions, K ion-ATPase and active membrane transport in hormone release. Metabolic requirements for hormone release and the role of Adenosine 3',5'-monophosphate in hormone release will be investigated. We propose to determine the rate of synthesis of ACTH and eventually GH and TSH by estimating the incorporation of labeled amino acids into hormone and by measuring the net production of hormone in cultures of pituitary tissue. With these methods we plan to determine the effect of stimulators on hormone secretion. The physiology of synthetic thyrotropin releasing factor on the physiology of TSH secretion in human subjects will be pursued and eventually the physiology of leutinizing hormone releasing factor on gonadotropin secretion in man will be studied. These studies are designed to gain further understanding of the mechanisms involved in the control of pituitary hormone production and secretion.